Object of the present invention is a box intercepting device particularly suitable for large containers of smelted metal.
It is known that containers of smelted metal have a lower discharge conduit which, up to some years ago, was generally kept closed through a casting rod coated with refractory. Such a casting rod is difficult in use and, as soon as high quality refractories became available, it was subsequently and gradually replaced with box intercepting devices the first embodiments of which, though not of common use, appeared some dozens of years ago.
Said box intercepting devices generally include a refractory plate supported by a metal frame and provided with a hole, said plate is slidable against a stationary refractory plate carried by a metal frame and provided with a hole arranged correspondingly to the outlet of the container of smelted metal.
The assignees of this invention patented various box dischargers of the above type which gave up to now very good results.
It is however to be noted that the refractory materials used in said box discharger are to be replaced periodically as soon as their wear degree is over a given level.
To this end, according to a previous patent of the assignees, the stationary refractory plate was blocked against the bottom of the smelted metal container through displaceable and adjustable guides, while the refractory plate slidable against the previous one for allowing alternatively the closing and opening of the casting hole was arranged in a tilting frame so as to replace it readily.
Such an arrangement, though very good under the operative point of view, requires at least two operators to mount and dismount it, if the size of the casting hole, corresponding to the size of the liquid metal container, is relatively large.
Up to now, the box dischargers of the above type have been used with good results in medium size containers of liquid metal.